Telephone-receiver.



H. R. STUART.

TELEPHONE RECEIVER.

APPLIUATION FILED 511111.21. 190e.

Patented Mar. 28, 1911.`

Si wuawoz @qu mieu/WHS HARVE R. STUART, 0F WHEELING, WEST VIRGINIA.

TELEPHONE-RECEIVER.

Specification of Letters Patent.

Patented Mar. 28, 1911.

Application tiled March 21, 1908, Serial No. 422,398.

To all 'whom it may concern:

'Be it known that I, HARVE R. STUART, a citizen of the United States, residing -at Wheeling', in the count;7 of Ohio and State of lVest Virginia, have invented certain new and useful Improvements in Telephone- Receivers, of which the following is a full, clear, and exact description My invention relates to telephone receivers for use iu ordinary telephone circuits, and also in connection with telegraphones, and has lor its objectthe combining of the magnetic and mechanical elements of a receiver in such a way as to produce a device which will respond to small or feeble currents and will produce strong acoustic etiects, and my invention consists in the features hereinatl' er set forth and claimed.

efereuce is hereby made to the accompanying drawing in which the same reference numerals are used to designate the corresponding parts in the several views of which,

Figure l is a side elevationof a receiver constructed in accordance With my invention. Fig. 2 is a 'section on the line 2 2 of Fig. 1. Figs. 3. '-1, 5, 6 and 7 are detail views ot certain of the elements of construction.

The receiver shown comprises a supporting ring` 1 of magnetic material such as iron or steel, which is provided withan inwardly extending flange 2 which forms a seat for the iron or steel diaphragm 3. A ring 4 of magnetic' materiai'is placed upon the diaphragm 3, as shown in Fig. 2. and

'the members l, 3 and 4 are held together by means of disks 5 of brass or other nonmagnetic material, said disks being seated within the ring 1 as shown, and clamped in position by.' the screws 6 suitably spaced around the ci reumference of the said disks.

The periphery of the ring 1 is drilled and tapped for the securing ot' the cores 7 ot four magnets Which'may be either permanent or electro-magnets, but which are shown as electro-magnets having energizing coils 8. These magnets also comprise, U- shaped arms or yokes 9,*whieh may be`of wrought iron and Whichare secured at their centers to the cores 7 by screws 10, and at their ends by screws 11 to a pair of wrought iron disks 12. The magnetic circuits ofthe four magnets are completed by tubular pole pieces 13 which are threaded within disks 5 and 12 and locked in position by nuts 14, thus providing for the ready adinner ends being adjacent thcjustment of said pole pieces toward and away from the diaphragm. These pole pieces are of likepolarity, and are arranged in axial alinenlent with each other, their the center of the diaphragm 3.

There are a pair of coils l5 disposed upon bases 1.5 surrounding the pole pieces 13 through which the voice currents are allowed to dow, and which are so Wound that a current in one direction will weaken 'the magnetic eld of one of the pole pieces 13, at the same time strengthening the field of the other pole piece, whereby the diaphragm or armature will be moved toward the latter pole piece; when the current is reversed. the diaphragm will be moved toward the other pole piece It will benoted that the ring 1 and plates 5 together with the diaphragm 3, form a pair of resonance chambers 16 and 17,` and that the pole pieces 13 act as sound conducting tubes forming outlets for the said resonance chambers 16 and 17, said tubes being adapted to be connected to ear pieces, megaphones, or listening devices. Another advantage of the tubular form of the pole pieces 13 1s that they are of greater diameter than solid pole pieces of the same cross sectional area. This increased diameter enlarges the circumference ot' the circle within which a given number of lines of force enter the diaphragm and therefore decreases its magnetic reluctance and `gives a greater total induction in the magnetic circuit.

Having 110W described my invention, what I claim, is:

1. In a receiver, the combination of the tube 13, the disk 12, thering 1, land one or more magnets for magnetizing the ring andtube with opposite polarity.

2, Tn a receiver, the combination of the ring l ot' magnetic material, the disks 12, and U-shaped members 9 magnetically connected at their centers to said ring and at their ends to said disks.

3. In a receiver'l` the combination lof the supporting ring 1. aplurality of cores 7 extending lradially from the exterior thereof, a pairof tubes 123 in axial aiinement with each other. and'means for connecting said cores and tubes in a plurality of magnetic circuits.

4. In a receiver, the combination of the supporting ring 1, the diaphragm 3 securedv thereto, and a plurality of magnets extending radially from the exterior of said ring and provided with common poles of like polarity ndjacenb `opposite faces of the movable portion of seid diaphragm. ,l

5. In a receiver, the Combination of the supporting, ringl, diaphragm B, and secur- Vit-liesses:

bei'.v` and means for oppositey golnrzug Said ring and tube. 10

In witness whereof, I subscribe my signature, in the presence of two Witnesses.

HARVE R. STUART.

ing plate 5, forming/a resonance chamber, a FRANK S. OBER, tube 13 forming an outlet for said cbem- WALDo M. CHAPIN.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

